Repetition Needed to Master Heart Sounds

Long bothered by a lack of proficiency with the stethoscope, lead author Michael Barrett, M.D., clinical associate professor of medicine and cardiologist at Temple University School of Medicine and Hospital, said such skills are critical to identifying dangerous heart conditions and minimizing dependence on expensive medical tests.

“It’s important to know when to order a costly echocardiogram or stress test. Managed care will not continue to tolerate this scattershot approach,” said Barrett. “Plus, internists are now tested on this skill for board recertification. Requirements for residents and other specialists are sure to follow.”

In previous studies, the rate of accurate heart sound identification ranged from 20 percent of medical students to fewer than 40 percent of internists. Traditional teaching methods for stethoscope skills like classroom lectures have proven inadequate.

“We hypothesized that cardiac auscultation is more of a technical skill and thus could be mastered through the use of intensive repetition,” said Barrett. For the study, 80 third-year medical students listened to an average of 500 repetitions each of six abnormal heart sounds (aortic stenosis, aortic regurgitation, mitral regurgitation, mitral stenosis, and S3 and S4 gallops) that mimicked heart conditions, such as narrowing of the heart valves and heart failure. The researchers gave CDs to the students, who typically converted the sounds to MP3 files so they could listen on their iPods.

With repetition, proficiency improved from approximately 39 percent to 89 percent. Students in the control group, who did not undergo the repetition, showed no improvement.